Furnace for the calcination of ores



(No Model.)

J DOUGLA-S, Jr. FURNACE FOR THE CALCULATION OF DEBS.

No. 307,924. i\\\\\\\\\\\\\\ Patented Nov. 11, 1884.

WI NEEEEE:

Uivlrrnn STATES PATENT @FFICF.

JAMES DOUGLAS, JR, OF PH(ENIXVILLE, PENNSYLVANIA.

FURNACE FOR THE CAL ClNATlON OF ORESn *JPECIFICAIION forming part of Letters Patent No. 307,924, dated November 11, 1884.

\ Application filed Decembcr23,188f2. (No model.) I

To all whom it may concern:

Be it known that I, JAIIES DOUGLAS, J r., a British subject, residing in the borough of Phoenixville, in the county of Chester and State of Pennsylvania, have invented a new and useful Furnace for the Galcination of Ores, for which I desire to obtain Letters Patent.

This invention relates to furnaces for the calcination of ores, and has for its object to so construct the furnace that the ores are continuously fed into and discharged from the cylinder, the products of combustion are kept separate from said ores and the gases evolved therefrom, and the requisite supply of air is furnished the said cylinder during the process of calcination.

To this end it consists in the novel construction hereinafter described and claimed.

In the drawings, Figure 1 is a vertical longitudinal section of my furnace. Fig. 2 is a transverse section on line 1? P, Fig. 1. Fig. 3 is a view of the feed end of the cylinder.

In all calcining furnaces it is desirable, and in those intended for the manufacture of sulphuric acid it is necessary, that the products of combustion be kept separate from the ores and the gases evolved from same. It is also necessary that a constant supply of air be admitted to the ore-chamber in order to secure the desired oxidation of the ores. Likewise it is desirable that no considerable excess of air be supplied, and that the draft of air be not so strong as to carry any great quantity of fine dust out of the ore-chamber into the acid-chamber. IVith these objects in view I have constructed my furnace as shown, and which will be now described in detail.

The cylinder 0 maybe constructed of iron with suitable fire-brick lining, and is provided with suitable rack-circles, O, which are rested on pinions 0 or' it may be supported in any other desired manner so it may be revolved. The feed end H is closed by a plate, h, having a central opening of sufficient size to admit the pipe (1, through which the ores are fed into the cylinder. The discharge end, G, of the cylinder. is arranged slightly lower than the feed end, and is closed by a plate, provided with a series of openings, arranged close to the inner walls of the cylinder. These openings are designed to permit the discharging of the roasted ore, and also to admit the necessary supply of air. It is desirable that the supply of air be varied with different ores, as is well known in the art, and to secure this I employ the damper-plate J, pivoted con centrically with the end plate q, and provided with a series of openings, j. This plate is movable, so as to bring the openings j to fully register with the openings 9, or to any extent desired during the operation, or to totally close said openings 9, in order to keep the cylinder warm'when at rest. The central flue, A, is extended through the cylinder, and has one'end carried into the fire-places e, and its opposite end connected with the chimney.

The object of this tube is to convey the products of combustion from the fire-place to the chimney, and heat the annular ore-containing space without the commingling of the gases of combustion with those evolved by the ores.

The operation of my furnace will be understood from the foregoing description.

I am aware that Patent No. 209,821 has been granted to one Manes, in which is shown a globe with a central fine through which the fire-place gases pass; but in this patent the feed of ore is intermittent, and the air is forced into the globe under pressure and independent of the ore-discharge.

I am also aware that patent to Smith, No. 109,355, shows a revolving cylinder having a central flue to protect the ore from the products of combustion; but in this case the cylinder is closed at the fire-place ends by imperforate heads, and the ore is intermittingly introduced through openings in the sides of the cylinders. In this case no provision is made for the introduction of air, but on the contrary the air is exhausted from the cylinder.

I am also aware that Patent No. 46,287 has been granted YVhite; but in this case the revolving cylinder contains several tubes, whlch form passages containing the ore to be.calcined, the said passages being designed to conduct the products of combustion from the furnace, whereas myobject is to keep the ore and products of combustion separate.

I am also aware of Patent No. 254,755, to vVetherell andVary, in which is shown a cylin der having a fire-place at each end,the heat and gas from one fire-place being carried into the cylinder by a tube that they may return in contact withthe ore to the discharge end. The heat and gas from the other fire-place travel together. One section of the cylinder has centrally-disposed pipes perforated with holes 5 for the distribution of air to the ore-mass in the cylinder; but in this case the air-feed is independent of the ore-discharge, and is notat the discharge end of the cylinder, and does .not, consequently, traverse the entire mass of IO the ore being operated on.

I do not claim the construction shown in patents above named, nor do I claim a central tube except in connection with a cylinder hav- -ing a continuous ore feed and discharge, and

a continuous air-admission and gas-discharge;

neither do I claim an air-valve except in connection with the oredischarge end of a cylinder having a continuous ore-discharge, which none of the patents before named show.

Having described my invention, what I claim, and desire to secure by Letters Patent, 1s

1. The combination of the cylinder having at one end an opening through which the ore may be continuously fed, and at its opposite end an opening through which the ore may be continuously discharged and air continuously admitted concurrently with said discharge, and a tight'central flue adapted to convey the products of combustion from the fire-place through the cylinder, substantially as set forth.

2. The roasting-cylinder having a tight central flue adapted to convey the products of combustion independent of and separate from the ore chamber, and provided at one end with a continuous ore-feed, and having its opposite end plate perforated with a circular series of openings close to the inner circumference of the cylinder, said end being fitted with a damper-plate journaled and rotatable concentrically with said discharge end plate, and provided with perforations suitably arranged whereby they may be adjusted to register fully with or vary the size of said openings, substantially as set forth.

JAMES DOUGLAS, JR.

WVitnesses:

ELLIS l3. Rnnvns, H. H. GILKYSON. 

